Pulmonary Embolism

Topic Overview

What is pulmonary embolism?

Pulmonary embolism is the sudden blockage of a major blood vessel (artery) in the lung, usually by a blood clot. In most cases, the clots are small and are not deadly, but they can damage the lung. But if the clot is large and stops blood flow to the lung, it can be deadly. Quick treatment could save your life or reduce the risk of future problems.

What are the symptoms?

The most common symptoms are:

• Sudden shortness of breath.
• Sharp chest pain that is worse when you cough or take a deep breath.
• A cough that brings up pink, foamy mucus.

Pulmonary embolism can also cause more general symptoms. For example, you may feel anxious or on edge, sweat a lot, feel lightheaded or faint, or have a fast heart rate or palpitations.

If you have symptoms like these, you need to see a doctor right away, especially if they are sudden and severe.

What causes pulmonary embolism?

In most cases, pulmonary embolism is caused by a blood clot in the leg that breaks loose and travels to the lungs. A blood clot in a vein close to the skin is not likely to cause problems. But having blood clots in deep veins (deep vein thrombosis) can lead to pulmonary embolism. More than 300,000 people each year have deep vein thrombosis or a pulmonary embolism.^{footnote 1}

Other things can block an artery, such as tumors, air bubbles, amniotic fluid, or fat that is released into the blood vessels when a bone is broken. But these are rare.

What increases your risk of pulmonary embolism?

Anything that makes you more likely to form blood clots increases your risk of pulmonary embolism. Some people are born with blood that clots too quickly. Other things that can increase your risk include:

• Being inactive for long periods. This can happen when you have to stay in bed after surgery or a serious illness, or when you sit for a long time on a flight or car trip.
• Recent surgery that involved the legs, hips, belly, or brain.
• Some diseases, such as cancer, heart failure, stroke, or a severe infection.
• Pregnancy and childbirth (especially if you had a cesarean section).
• Taking birth control pills or hormone therapy.
• Smoking.

You are also at higher risk for blood clots if you are an older adult (especially older than 70) or extremely overweight (obese).

How is pulmonary embolism diagnosed?

It may be hard to diagnose pulmonary embolism, because the symptoms are like those of many other problems, such as a heart attack, a panic attack, or pneumonia. A doctor will start by doing a physical exam and asking questions about your past health and your symptoms. This helps the doctor decide if you are at high risk for pulmonary embolism.

Based on your risk, you might have tests to look for blood clots or rule out other causes of your symptoms. Tests may include blood tests, a CT angiogram, and a ventilation-perfusion lung scan.

How is it treated?

Doctors usually treat pulmonary embolism with medicines called anticoagulants. They are often called blood thinners, but they don't really thin the blood. They help prevent new clots and keep existing clots from growing.

Most people take a blood thinner for a few months. People at high risk for blood clots may need it for the rest of their lives.

If symptoms are severe and life-threatening, "clot-busting" drugs called thrombolytics may be used. These medicines can dissolve clots quickly, but they increase the risk of serious bleeding. Another option is surgery or a minimally invasive procedure to remove the clot (embolectomy).

Some people may have a filter put into the large vein (vena cava) that carries blood from the lower body to the heart. A vena cava filter helps keep blood clots from reaching the lungs.

If you have had pulmonary embolism once, you are more likely to have it again. Blood thinners can help reduce your risk, but they increase your risk of bleeding. If your doctor prescribes blood thinners, be sure you understand how to take your medicine safely.

You can reduce your risk of pulmonary embolism by doing things that help prevent blood clots in your legs.

• Avoid sitting for long periods. Get up and walk around every hour or so, or flex your feet often.
• Get moving as soon as you can after surgery.
• When you travel, drink extra fluids. But avoid drinks with alcohol or caffeine.
• Wear compression stockings if you are at high risk.
• If you take blood thinners, take them just the way your doctor tells you to.

Frequently Asked Questions